It has heretofore been proposed to provide a plurality of large diameter wheels, aligned in a straight line under the sole of a shoe, to serve as a roller skate as in U.S. Pat. No. 1,497,224 to Ormiston of June 10, 1924 or small diameter wheels so aligned as in U.S. Pat. No. 3,339,936 to Hamlin of Sept. 5, 1967 and U.S. Pat. No. 3,387,852 to DeSarro of June 11, 1968.
It has also been proposed to provide a single large diameter wheel on one side of the centre of a shoe to form a single wheel roller skate as in U.S. Pat. No. 2,931,012 to Kosach of Mar. 29, 1960 and to provide two large diameter wheels on one side of the front and rear of a shoe as in U.S. Pat. No. 1,552,541 to Clark of Sept. 8, 1925 and U.S. Pat. No. 3,885,804 to Cudmore of May 27, 1975. In both patents the wheels are canted outwardly so that the ground engaging portions are under the axial centre line of the sole plate. This is also true of the two wheel roller skates disclosed in German Pat. No. 215,734 and Italian Pat. No. 425,889.